The Liberal Democrats have voted in favour of the legalisation of cannabis - the first main UK party to support such a radical move.

The party's leadership had recommended decriminalising the drug but delegates went a step further and chose legalisation, at the spring conference in Manchester.

[Addicts] have already lost their jobs, their homes and their families - prison won't help, and it probably won't deter

Harriet SmithLiberal Democrats

They also voted for an end to imprisonment for the possession of any illegal drug - including heroin and cocaine - and backed the downgrading of ecstasy from a Class A to a Class B drug.

Liberal Democrat home affairs spokesman Simon Hughes said the move was "responsible, realistic and progressive".

Describing the prosecution of cannabis users as "a waste of time", he said his party's approach stood for "help for the addict, punishment for the dealer".

Abolishing jail sentences for... cocaine and heroin would lead to more drug use and more drug-related crime

Labour spokeswoman

The party's leader Charles Kennedy has previously backed legalisation but did not take part in Saturday's discussion or vote.

Afterwards, Mr Kennedy said that taken as a whole, the package - which calls for more rehabilitation facilities and tougher sentences for those caught selling drugs near schools - was an appropriate response to the problem.

But the Labour party denounced the move, saying the Liberal Democrats had "lost touch with the real world" where drugs policy is concerned.

"Ecstasy is a dangerous drug that kills and grading it from Class A to Class
B would be foolhardy and irresponsible," a spokeswoman said.

"Abolishing jail sentences for drugs like cocaine and heroin would lead to
more drug use and more drug-related crime."

'Honest debate'

Delegates conceded that legalising cannabis would take time to implement.

But in the meantime, they would no longer prosecute people for possessing or growing the drug for their own use.

Earlier, Mr Kennedy said that having the confidence and maturity to discuss the issue honestly and openly did the party "no harm".

Mr Hughes said delegates had been carefully considering the issues for two years, and that there were "close votes on some of the issues under debate".

Cannabis users would no longer face prosecution

One speaker, barrister Jonathan Marks, had argued that ending imprisonment for hard drugs would be a huge mistake.

"If we were to abolish imprisonment for possession, and therefore for use, of Class A drugs, we would be sending entirely the wrong message to the public at large and especially to young people, about hard drugs," he said.

But another speaker, Harriet Smith, countered that imprisoning drug users simply does not work.

"They've already lost their jobs, their homes and their families," she said. "Prison won't help, and it probably won't deter. In fact it can make matters far worse.

"I know people who have gone inside clean and come out seriously addicted."